The developing world has had no shortage of dictators who made lofty promises to uplift the poor and build a powerful nation. Few ever delivered.

But then there was South Korea's Park Chung Hee. A general who took control of the country in a 1961 coup, he ruled, often with an iron fist, for 18 years. Yet he was deeply moved by South Korea's destitution. In the early 1960s, the country's per capita income was just over $100, and the economy depended on American aid. Park, a virulent nationalist, vowed to do something about it. "I had to break, once and...